Light emitting element and light emitting device

ABSTRACT

Provided are a light emitting element and a light emitting device with improved light emission intensity distribution. A light emitting element includes a light-transmissive substrate, an n-type semiconductor layer, a first p-type semiconductor layer, a first p-side electrode, a first n-side electrode, a second p-type semiconductor layer, a second p-side electrode, and a second n-side electrode. A light emitting device includes the light emitting element, and an external connection electrode provided at the light emitting element on a side opposite to the light-transmissive substrate. The external connection electrode includes an n-side external connection electrode connected to the first n-side electrode and the second n-side electrode, a first p-side external connection electrode connected to the first p-side electrode, and a second p-side external connection electrode connected to the second p-side electrode.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 15/210,302, filed Jul. 14, 2016, which claims priority under 35U.S.C. § 119 to Japanese Patent Application No. 2015-142461, filed Jul.16, 2015, and Japanese Patent Application No. 2016-135407, filed Jul. 7,2016. The contents of these applications are incorporated herein byreference in their entireties.

BACKGROUND 1. Technical Field

The present disclosure relates to a light emitting element and a lightemitting device.

2. Description of Related Art

In the field of light emitting elements used in light emitting devices,various development efforts have conventionally been made for achievingan even light emission intensity distribution in a light extractionsurface. For example, a light emitting element used in a light emittingdevice disclosed in WO2009/019836 has at least two regions, namely, anedge portion and a region inner than the edge portion. The lightemitting element is provided with an anode electrode at each of the edgeportion and the region inner than the edge portion, and is furtherprovided with a cathode electrode at the region inner than the edgeportion, which cathode electrode is shared with the edge portion.

On the other hand, in a light emitting element, the current density isgreater in a region where the distance between an anode electrode (ap-side electrode) and a cathode electrode (an n-side electrode) isshort, which tends to result in uneven light emission. Accordingly, inview of unevenness in the current density attributed to disposition ofthe electrodes also, it is considered that the light emission intensitydistribution is susceptible to improvement.

SUMMARY

An objective of embodiments of the present disclosure is to provide alight emitting element and a light emitting device with an improvedlight emission intensity distribution.

In order to achieve the objective stated above, a light emitting elementaccording to the present disclosure includes: a light-transmissivesubstrate; a first semiconductor stacked-layer body having a firstn-type semiconductor layer provided above part of the light-transmissivesubstrate, and a first p-type semiconductor layer provided above thefirst n-type semiconductor layer, the first p-type semiconductor layerbeing provided with a first hole; a first p-side electrode provided onthe first p-type semiconductor layer; a first n-side electrode having aportion above the first p-side electrode, extending into the first hole,and being electrically connected to the first n-type semiconductorlayer; a second semiconductor stacked-layer body having a second n-typesemiconductor layer provided above the light-transmissive substrate andaround the first semiconductor stacked-layer body in a plan view, and asecond p-type semiconductor layer provided above the second n-typesemiconductor layer, the second p-type semiconductor layer beingprovided with a second hole; a second p-side electrode provided on thesecond p-type semiconductor layer; and a second n-side electrode havinga portion above the second p-side electrode, extending into the secondhole, and being electrically connected to the second n-typesemiconductor layer.

Further, in order to achieve the objective stated above, a lightemitting element according to other embodiment of the present disclosureincludes: a light-transmissive substrate; an n-type semiconductor layerprovided above the light-transmissive substrate; a first p-typesemiconductor layer provided above part of the n-type semiconductorlayer and having a first hole; a first p-side electrode provided on thefirst p-type semiconductor layer; a first n-side electrode having aportion above the first p-side electrode, extending into the first hole,and being electrically connected to the n-type semiconductor layer; asecond p-type semiconductor layer provided above the n-typesemiconductor layer and around the first p-type semiconductor layer in aplan view, the second p-type semiconductor layer having a second hole; asecond p-side electrode provided on the second p-type semiconductorlayer; and a second n-side electrode having a portion above the secondp-side electrode, extending into the second hole, and being electricallyconnected to the n-type semiconductor layer.

Still further, a light emitting device according to an embodiment of thepresent disclosure includes: the light emitting element; and an externalconnection electrode provided at the light emitting element on a sideopposite to the light-transmissive substrate, wherein the externalconnection electrode includes: an n-side external connection electrodeconnected to the first n-side electrode and the second n-side electrode;a first p-side external connection electrode connected to the firstp-side electrode; and a second p-side external connection electrodeconnected to the second p-side electrode.

Still further, a light emitting device according to other embodiment ofthe present disclosure includes: the light emitting element; and anexternal connection electrode provided at the light emitting element ona side opposite to the light-transmissive substrate, wherein theexternal connection electrode includes: a first n-side externalconnection electrode connected to the first n-side electrode; a secondn-side external connection electrode connected to the second n-sideelectrode; and a p-side external connection electrode connected to thefirst p-side electrode and the second p-side electrode.

Still further, a light emitting device according to another embodimentof the present disclosure includes: the light emitting element; and anexternal connection electrode provided at the light emitting element ona side opposite to the light-transmissive substrate, wherein theexternal connection electrode includes: a first n-side externalconnection electrode connected to the first n-side electrode; a secondn-side external connection electrode connected to the second n-sideelectrode; a first p-side external connection electrode connected to thefirst p-side electrode; and a second p-side external connectionelectrode connected to the second p-side electrode.

The light emitting element according to the embodiments of the presentdisclosure can reduce unevenness in the current density, and thereforecan improve the light emission intensity distribution.

The light emitting device according to the embodiments of the presentdisclosure can reduce unevenness in the current density in the lightemitting element, and therefore can improve the light emission intensitydistribution.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view schematically showing a lightemitting element, a light emitting device, and a light source accordingto an embodiment.

FIG. 2 is a plan view schematically showing a wavelength conversionmember on the light emitting device according to the embodiment.

FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2.

FIG. 4 is a top view schematically showing a light emitting element anda light emitting device according to a first embodiment.

FIG. 5 is a bottom view schematically showing the light emitting elementand the light emitting device according to the first embodiment.

FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5.

FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 5.

FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 5.

FIG. 9 is an explanatory diagram schematically showing the dispositionregion of a cover electrode in the light emitting device according tothe first embodiment.

FIG. 10 is an explanatory diagram schematically showing the dispositionregion of an interlayer insulating film in the light emitting deviceaccording to the first embodiment.

FIG. 11 is an explanatory diagram schematically showing the dispositionregions of n-side electrodes and p-side electrodes in the light emittingdevice according to the first embodiment.

FIG. 12 is an explanatory diagram schematically showing the dispositionregion of an insulating protective film in the light emitting deviceaccording to the first embodiment.

FIG. 13 is a bottom view schematically showing a light emitting elementand a light emitting device according to a second embodiment.

FIG. 14 is a cross-sectional view taken along line XIV-XIV in FIG. 13.

FIG. 15 is a bottom view schematically showing a light emitting elementand a light emitting device according to a third embodiment.

FIG. 16 is a cross-sectional view taken along line XVI-XVI in FIG. 15.

FIG. 17 is a bottom view schematically showing a light emitting deviceaccording to a fourth embodiment.

FIG. 18 is a bottom view schematically showing a light emitting deviceaccording to a fifth embodiment.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following, a description will be given of a light emittingelement and a light emitting device according to embodiments of thepresent invention.

Note that, the drawings referred to in the following descriptionschematically show the present invention, and therefore the scale,interval, or positional relationship of the constituent members may beexaggerated or the constituent members may be partially omitted.Further, plan views and cross-sectional views may not agree with eachother in the scale, thickness, or interval. Still further, in thefollowing description, like names and reference characters denote likeor similar constituent members in principle, and the detaileddescription thereof will be omitted as appropriate.

First Embodiment

[Structure of Light Emitting Device]

Firstly, with reference to FIGS. 1 to 4, a description will be given ofthe structure of a light emitting element and a light emitting deviceaccording to a first embodiment of the present invention. A light source2 shown in FIG. 1 includes a light emitting device 100, a wavelengthconversion member 9 provided on a light-transmissive substrate 10 sideof the light emitting device 100, and a Fresnel lens 6 provided oppositeto the light-transmissive substrate 10 with reference to the wavelengthconversion member 9. The light source 2 may be used as illumination, ormay be installed in an external apparatus unit such as a flash module ofa camera, for example. An exemplary external apparatus unit may be acamera-equipped mobile terminal such as a smartphone.

[Light Emitting Device]

The light emitting device 100 includes a light emitting element 1 andexternal connection electrodes 8. The light emitting device 100 ispackaged having its periphery covered by a light reflecting member.

The light emitting element 1 may be, for example, a semiconductor lightemitting element such as a light emitting diode chip. The upper surfaceof the light emitting element 1 is the light emitting surface, and theexternal connection electrodes 8 are provided at the lower surface ofthe light emitting element 1, i.e., on the side opposite to the lightemitting surface. For example, the light emitting element 1 includes thelight-transmissive substrate 10 positioned on the light emitting surfaceside and a semiconductor stacked-layer body 20 provided at the surfaceof the light-transmissive substrate 10 opposite to the light emittingsurface, and the external connection electrodes 8 are formed on thesurface of the semiconductor stacked-layer body 20. Note that, thedescription is given of the overview of the light emitting element 1herein, and a detailed description thereof will be given later.

The semiconductor stacked-layer body 20 includes, for example in orderfrom the light-transmissive substrate 10 side, an n-type semiconductorlayer, an active layer, and a p-type semiconductor layer. Thesemiconductor layers may be composed of, for example, a semiconductormaterial of a group III-V compound semiconductor, a group II-VI compoundsemiconductor or the like. Specifically, a nitride-based semiconductormaterial such as In_(X)Al_(Y)Ga_(1-X-Y)N (0≤X, 0≤Y, X+Y≤1) may be used(for example, InN, AlN, GaN, InGaN, AlGaN, InGaAlN or the like).

In the semiconductor stacked-layer body 20, a cathode terminal of theexternal connection electrodes 8 is connected to the n-typesemiconductor layer, and anode terminal of the external connectionelectrodes 8 is connected to the p-type semiconductor layer. As shown inFIG. 4, in a plan view, the semiconductor stacked-layer body 20 includesa first semiconductor region 21, and a second semiconductor region 22provided around the first semiconductor region 21.

The first semiconductor region 21 is provided with first holes 21 h thatpenetrate through the p-type semiconductor layer to expose the n-typesemiconductor layer (see FIG. 6). The second semiconductor region 22 isprovided with second holes 22 h that penetrate through the p-typesemiconductor layer to expose the n-type semiconductor layer (see FIG.7). The first holes 21 h and the second holes 22 h are formed by removalof the p-type semiconductor layer, the active layer, and part of then-type semiconductor layer above the light-transmissive substrate 10.The p-type semiconductor layer in the first semiconductor region 21 andthe p-type semiconductor layer in the second semiconductor region 22 areseparated from each other, and therefore the first semiconductor region21 and the second semiconductor region 22 can emit light independentlyof each other. In the light emitting element 1, the first semiconductorregion 21 serves as the first light emitting portion, and the secondsemiconductor region 22 serves as the second light emitting portion.

In the following description, the p-type semiconductor layer in thefirst semiconductor region 21 is referred to as a first p-typesemiconductor layer 21 p. Similarly, the p-type semiconductor layer inthe second semiconductor region 22 is referred to as a second p-typesemiconductor layer 22 p. Note that, the n-type semiconductor layer iscontinuously formed across the first semiconductor region 21 and thesecond semiconductor region 22, and simply referred to as an n-typesemiconductor layer 21 n.

The external connection electrodes 8 are provided opposite to thelight-transmissive substrate 10 of the light emitting element 1 withreference to the semiconductor stacked-layer body 20. The externalconnection electrodes 8 include an n-side external connection electrode80 n, a first p-side external connection electrode 81 p, and a secondp-side external connection electrode 82 p. The n-side externalconnection electrode 80 n is a cathode terminal shared by the firstsemiconductor region 21 and the second semiconductor region 22. Such ashared cathode terminal simplifies the mounting of the light emittingdevice 100, and additionally improves heat releasing property by virtueof the increased bonding area with the mounting substrate. Further, thefirst p-side external connection electrode 81 p is an anode terminal forthe first semiconductor region 21. The second p-side external connectionelectrode 82 p is an anode terminal for the second semiconductor region22.

[Wavelength Conversion Member 9]

The wavelength conversion member 9 has its lower surface opposed to thelight emitting surface of the light emitting element 1, and covers atleast part of the light emitting surface of the light emitting element1. The wavelength conversion member 9 is excited by part of lightemitted from the light emitting element 1, and emits light having awavelength different from that of the light from the light emittingelement 1. As shown in FIG. 2, the wavelength conversion member 9 coversthe entire light emitting surface of the light emitting element 1. Theouter circumferential surface (outer side surface) of the wavelengthconversion member 9 is positioned outside the outer side surface of thelight emitting element 1. The wavelength conversion member 9 includes afirst fluorescent material layer 91, a second fluorescent material layer92, and a light-transmissive member 93.

In a plan view, the first fluorescent material layer 91 covers the firstsemiconductor region 21 of the light emitting element 1. That is, in aplan view, the first fluorescent material layer 91 covers the firstp-type semiconductor layer 21 p of the light emitting element 1. Thefirst fluorescent material layer 91 includes a fluorescent material(hereinafter referred to as a first fluorescent material) and alight-transmissive member. Similarly, the second fluorescent materiallayer 92 includes a fluorescent material (hereinafter referred to as asecond fluorescent material) and a light-transmissive member. Thewavelength of a fluorescence in the second fluorescent material layer 92gets longer than that in the first fluorescent material layer 91.

An exemplary first fluorescent material may be a fluorescent materialcontaining a rare-earth element, specifically, a garnet-type fluorescentmaterial that contains at least one element selected from the groupconsisting of Y, Lu, Sc, La, Gd, Tb, and Sm, and at least one elementselected from the group consisting of Al, Ga, and In. In particular, analuminum-garnet-based fluorescent material contains Al and at least oneelement selected from the group consisting of Y, Lu, Sc, La, Gd, Tb, Eu,Ga, In, and Sm, and activated by at least one element selected from therare-earth elements. The aluminum-garnet-based fluorescent materialemits light by being excited with visible light or ultraviolet lightemitted from the light emitting element 1. Exemplary fluorescentmaterials include an yttrium-aluminum-oxide-based fluorescent material(a YAG-based fluorescent material), Tb_(2.95)Ce_(0.05)Al₅O₁₂,Y_(2.90)Ce_(0.05)Tb_(0.05)Al₅O₁₂, Y_(2.94)Ce_(0.05)Pr_(0.01)Al₅O₁₂,Y_(2.90)Ce_(0.05)Pr_(0.05)Al₅O₁₂ and the like. Of these, particularly inthe present embodiment, yttrium-aluminum-oxide-based fluorescentmaterials of two or more types that contain Y, is activated by Ce or Pr,and differ from each other in composition are used.

In a plan view, the second fluorescent material layer 92 annularlysurrounds the first fluorescent material layer 91, and covers the secondsemiconductor region 22 of the light emitting element 1. That is, in aplan view, the second fluorescent material layer 92 covers the secondp-type semiconductor layer 22 p of the light emitting element 1.

The second fluorescent material layer 92 preferably includes, forexample, a nitride-based fluorescent material as the second fluorescentmaterial. The nitride-based fluorescent material contains N, and furthercontains at least one element selected from the group consisting of Be,Mg, Ca, Sr, Ba, and Zn, and at least one element selected from the groupconsisting of C, Si, Ge, Sn, Ti, Zr, and Hf, and is activated by atleast one element selected from the rare-earth elements. Exemplarynitride-based fluorescent materials include (Sr_(0.97)Eu_(0.03))₂Si₅N₈,(Ca_(0.985)Eu_(0.015))₂Si₅N₈, (Sr_(0.679)Ca_(0.291)Eu_(0.03))₂Si₅N₈, andthe like.

<Light-Transmissive Member 93>

The light-transmissive member 93 is provided between the firstfluorescent material layer 91 and the second fluorescent material layer92, and around the second fluorescent material layer 92. This allows theFresnel lens 6 to efficiently use light extracted from the firstfluorescent material layer 91 and light extracted from the secondfluorescent material layer 92. The light-transmissive resin composingthe light-transmissive member 93 may be thermosetting resin such assilicone resin, silicone-modified resin, epoxy resin, phenolic resin orthe like, or thermoplastic resin such as polycarbonate resin, aclyricresin, methylpentene resin, polynorbornene resin or the like. Inparticular, silicone resin which exhibits excellent lightfastness andheat-resistance is suitable. Further, the light-transmissive member 93may be replaced by a light-shielding member such as a metal film, whichalso enables extraction of light from each of the fluorescent materiallayers 91 and 92. Further, the light-transmissive member 93 can bedispensed with, and the first fluorescent material layer 91 and thesecond fluorescent material layer 92 may be in contact with each other,and the second fluorescent material layer 92 and a light reflectingmember 7 a, which is described below, may be in contact with each other.

The light reflecting member 7 a is provided around the wavelengthconversion member 9. The light reflecting member 7 a covers the outercircumference of the wavelength conversion member 9, and preferably isin contact with the wavelength conversion member 9. This reduces leakageof light from the side surface of the wavelength conversion member 9. Asa result, the difference in the output between light extracted from thefirst fluorescent material layer 91 and light extracted from the secondfluorescent material layer 92 can be reduced, and the wavelengthconversion member 9 can be held by the light reflecting member 7 a.Therefore, the light reflecting member 7 a is preferably in contact withthe entire side surface of the wavelength conversion member 9. Thus,leakage of light from the side surface of the wavelength conversionmember 9 is effectively reduced and the wavelength conversion member 9can be surely held.

In the example shown in FIGS. 2 and 3, a light reflecting member 7 bcovers the side surface and part of the lower surface of the lightemitting element 1 while exposing the surfaces of the externalconnection electrodes 8. The light reflecting member 7 b is in contactwith one surface of a circumferential portion 301 of the secondfluorescent material layer 92 of the wavelength conversion member 9,which one surface is on the light-transmissive substrate 10 side. Thelight reflecting member 7 b is in contact with the lower surface of thelight reflecting member 7 a, and protects the light emitting element 1with the light reflecting member 7 a. Further, since the light outputfrom the side surface of the light emitting element 1 is reflected atthe interface between the light reflecting member 7 b and the lightreflecting member 7 a and can be extracted via the wavelength conversionmember 9, the light extraction efficiency improves. The bottom surfaceof the light reflecting member 7 b is formed to be substantially flat.At that bottom surface, the surfaces of the external connectionelectrodes 8 are exposed. The bottom surface of the light reflectingmember 7 b is the mounting surface side of the light emitting device100. Note that, a light-transmissive member may be provided across thecircumferential portion 301 of the second fluorescent material layer 92and the side surface of the light-transmissive substrate 10. Then, sincethe light output from the side surface of the light emitting element 1can be reflected at the interface between this light-transmissive memberand the light reflecting member 7 b toward the wavelength conversionmember 9, the light extraction efficiency further improves.

<Light-Reflective Members 7 a, 7 b>

The light reflecting member 7 a and the light reflecting member 7 b maybe composed of light reflecting resin. The light reflecting resin refersto resin that has high reflectivity to light from the light emittingelement 1, and for example, refers to resin having a reflectivity of 70%or more. The light reflecting resin is, for example, light-transmissiveresin in which a light reflecting substance is dispersed. Suitably, thelight reflecting substance is, for example, titanium oxide, silicondioxide, titanium dioxide, zirconium dioxide, potassium titanate,alumina, aluminum nitride, boron nitride, mullite or the like. The lightreflecting substance may be granular, fibrous, or flaky. In particular,a fibrous light reflecting substance is preferable because it exhibitsalso the effect of reducing the thermal expansion coefficient of thelight reflecting member 7 a and the light reflecting member 7 b, therebyreducing the difference in the thermal expansion coefficient between,for example, the light reflecting member 7 a and the light reflectingmember 7 b and the light emitting element 1. The resin material as thelight reflecting resin is particularly preferably thermosettinglight-transmissive resin such as silicone resin, silicone-modifiedresin, epoxy resin, or phenolic resin.

[Fresnel Lens 6]

The Fresnel lens 6 is a thin lightweight lens that has the refractionproperty similar to that of a convex lens. The Fresnel lens 6 receiveslight at one surface (a flat surface) and outputs the light from othersurface (a concentrically shaped surface) to be converged forward. TheFresnel lens 6 is mounted such that its center substantially agrees withthe center of the first fluorescent material layer 91 of the wavelengthconversion member 9, and the center of the first semiconductor region 21of the light emitting element 1. As shown in FIG. 1, the Fresnel lens 6covers the entire light output surface of the first fluorescent materiallayer 91 and the second fluorescent material layer 92 of the wavelengthconversion member 9. Note that, the outer circumferential edge of theFresnel lens 6 is disposed outside the second fluorescent material layer92.

The light source 2 integrating the Fresnel lens 6, the light emittingdevice 100, and the wavelength conversion member 9 can be installed inan external apparatus unit. Alternatively, the Fresnel lens 6 may bepreviously provided in the apparatus unit where the light source 2 is tobe implemented. Then, mounting the light emitting device 100 and thewavelength conversion member 9 on the apparatus unit can implement thelight source 2.

Next, with reference to FIGS. 4 to 8, a detailed description will begiven of the light emitting element 1.

[Light Emitting Element 1]

As shown in FIGS. 4 to 8, the light emitting element 1 includes thelight-transmissive substrate 10, the first semiconductor region 21, thesecond semiconductor region 22, a first p-side light reflecting layer 31p, a second p-side light reflecting layer 32 p, a cover electrode 40, aninterlayer insulating film 50, a first p-side electrically conductivelayer 61 p, a first n-side electrode 61 n, a second p-side electricallyconductive layer 62 p, a second n-side electrode 62 n, and an insulatingprotective film 70.

On the insulating protective film 70, the n-side external connectionelectrode 80 n, the first p-side external connection electrode 81 p, andthe second p-side external connection electrode 82 p (hereinafter alsocollectively referred to as the external connection electrodes 8) areprovided.

As shown in FIGS. 4 to 6 and 11, the light emitting element 1 includes,at the first semiconductor region 21, the first n-side electrode 61 n,and the first p-side light reflecting layer 31 p as a first p-sideelectrode provided on the first p-type semiconductor layer 21 p.

As shown in FIGS. 4, 5, 7, 8 and 11, the light emitting element 1includes, at the second semiconductor region 22, the second n-sideelectrode 62 n, and the second p-side light reflecting layer 32 p as asecond p-side electrode provided on the second p-type semiconductorlayer 22 p.

<Light-Transmissive Substrate 10>

The light-transmissive substrate 10 may be composed of, for example, alight-transmissive insulating material such as sapphire (Al₂O₃), or asemiconductor material such as gallium nitride (GaN). Thislight-transmissive substrate 10 may be thinned by polishing.

<First Semiconductor Region 21>

As shown in FIG. 6, the first semiconductor region 21 includes then-type semiconductor layer 21 n, a first active layer 21 a, and thefirst p-type semiconductor layer 21 p, which are provided above thelight-transmissive substrate 10. These semiconductor layers may eachhave a single-layer structure, or may have a stacked-layer structuremade up of layers of different composition or thickness, or asuperlattice structure. In particular, the first active layer 21 apreferably has a single quantum well structure or a multi quantum wellstructure in which thin films exhibiting the quantum effect are stacked.

As shown in FIG. 4, the outer edge of the first p-type semiconductorlayer 21 p in a plan view is preferably circular, such that the Fresnellens 6 is effectively used.

As shown in FIG. 6, the first p-type semiconductor layer 21 p isprovided above part of the n-type semiconductor layer 21 n, and providedwith the first holes 21 h. The first p-type semiconductor layer 21 p isprovided with a plurality of first holes 21 h. The plurality of firstholes 21 h are arranged along the outer edge portion of the first p-typesemiconductor layer 21 p, whereby the current is more evenly supplied tothe first semiconductor region 21. Further, the circularly arrangedfirst holes 21 h enables light emission that makes full use of theFresnel lens 6. Further, the plurality of first holes 21 h may bearranged substantially at regular intervals.

In each first hole 21 h, the first p-type semiconductor layer 21 p, thefirst active layer 21 a, and part of the n-type semiconductor layer 21 nare removed above the light-transmissive substrate 10. The bottomsurface of the first hole 21 h is the exposed surface of the n-typesemiconductor layer 21 n. The side surface of the first hole 21 h iscovered by the interlayer insulating film 50. At the bottom surface ofthe first hole 21 h, a circular n-side opening 51 n of the interlayerinsulating film 50 is provided. Through the n-side opening 51 n, thefirst n-side electrode 61 n and the n-type semiconductor layer 21 n arein contact with each other and electrically connected to each other.Note that, the shape of the first hole 21 h may be, for example,circular or elliptic as seen from above.

The diameter of the first hole 21 h can be set as appropriate dependingon the size of the semiconductor stacked-layer body 20. A reduceddiameter of the first hole 21 h increases the light emitting region,because it reduces the partial removal area of the first active layer 21a and others. An increased diameter of the first hole 21 h suppresses anincrease in the forward voltage, because it increases the contact areabetween the first n-side electrode 61 n and the n-type semiconductorlayer 21 n.

<Second Semiconductor Region 22>

The second semiconductor region 22 is similarly structured as the firstsemiconductor region 21, but different from the first semiconductorregion 21 in the disposition position. As shown in FIG. 4, the firstsemiconductor region 21 and the second semiconductor region 22 arepreferably equivalent in the area in a plan view in view of the currentdensity. As shown in FIGS. 7 and 8, the second semiconductor region 22includes the n-type semiconductor layer 21 n, a second active layer 22a, and the second p-type semiconductor layer 22 p which are providedabove the light-transmissive substrate 10.

As shown in FIG. 4, the outer edge of the second p-type semiconductorlayer 22 p in a plan view is circular. Here, the inner edge of thesecond p-type semiconductor layer 22 p in a plan view is circular. Thatis, the second p-type semiconductor layer 22 p is annular, which enablesmore effective use of the Fresnel lens 6.

As shown in FIGS. 7 and 8, the second p-type semiconductor layer 22 p isprovided above part of the n-type semiconductor layer 21 n, and providedwith the second holes 22 h. The second p-type semiconductor layer 22 pis provided with a plurality of second holes 22 h. The plurality ofsecond holes 22 h are arranged along the inner edge portion of thesecond p-type semiconductor layer 22 p, whereby the current is moreevenly supplied to the second semiconductor region 22. Further, sincethe plurality of second holes 22 h are arranged adjacent to the firstsemiconductor region 21, they also contribute toward current diffusionin the first semiconductor region 21. Still further, the plurality ofsecond holes 22 h may be arranged substantially at regular intervals.Still further, the plurality of second holes 22 h are preferablyarranged closer to the inner edge portion of the second p-typesemiconductor layer 22 p than to the outer edge portion thereof. Thisminimizes the entire length of the second n-side electrode 62 nintegrally connecting the plurality of second holes 22 h, whichsuppresses an increase in the forward voltage attributed to wiringresistance.

In each second hole 22 h, the second p-type semiconductor layer 22 p,the second active layer 22 a, and part of the n-type semiconductor layer21 n are removed above the light-transmissive substrate 10. The bottomsurface of the second hole 22 h is the exposed surface of the n-typesemiconductor layer 21 n. The side surface of the second hole 22 h iscovered by the interlayer insulating film 50. At the bottom surface ofthe second hole 22 h, a circular n-side opening 52 n of the interlayerinsulating film 50 is provided. Through the n-side opening 52 n, thesecond n-side electrode 62 n and the n-type semiconductor layer 21 n arein contact with each other and electrically connected to each other.Note that, the shape of the second hole 22 h may be, for example,circular or elliptic as seen from above. The diameter of the second hole22 h can be set as appropriate depending on the size of thesemiconductor stacked-layer body 20.

As shown in FIG. 7, the boundary between an outer edge portion 22 s ofthe n-type semiconductor layer 21 n and the second p-type semiconductorlayer 22 p is covered by the second n-side electrode 62 n and theinterlayer insulating film 50, and not covered by the cover electrode40.

<First P-side Light Reflecting Layer 31 p>

As shown in FIG. 6, the first p-side light reflecting layer 31 p isconnected to substantially the entire upper surface of the first p-typesemiconductor layer 21 p. The first p-side light reflecting layer 31 phas openings being concentric to the first holes 21 h at positionscorresponding to the first holes 21 h of the n-type semiconductor layer21 n (see FIG. 9). As used herein, substantially the entire uppersurface refers to the region in the upper surface of the first p-typesemiconductor layer 21 p except for the outer edge and the inner edgesaround the first holes 21 h. For example, the first p-side lightreflecting layer 31 p preferably covers 90% or more of the area of theupper surface of the first p-type semiconductor layer 21 p.

The first p-side light reflecting layer 31 p is a layer for evenlydiffusing the current supplied via the first p-side electricallyconductive layer 61 p to the entire first p-type semiconductor layer 21p. Further, the first p-side light reflecting layer 31 p has anexcellent light reflecting property, and serves also as a layer thatdownwardly reflects light having emitted from the light emitting element1, that is, toward the light extraction surface.

<Second P-side Light Reflecting Layer 32 p>

The second p-side light reflecting layer 32 p is similarly structured asthe first p-side light reflecting layer 31 p, but different from thefirst p-side light reflecting layer 31 p in the disposition position.

As shown in FIGS. 7 and 8, the second p-side light reflecting layer 32 pis connected to substantially the entire upper surface of the secondp-type semiconductor layer 22 p. The second p-side light reflectinglayer 32 p has openings being concentric to the second holes 22 h atpositions corresponding to the second holes 22 h of the n-typesemiconductor layer 21 n (see FIG. 9).

The first p-side light reflecting layer 31 p and the second p-side lightreflecting layer 32 p may be made of a metal material that has excellentelectrical conductivity and light reflecting property. In particular,metal materials having an excellent light reflecting property in thevisible light region suitably include Ag, Al, Pt, Rh, Ir and alloy ofwhich main component is such metal. Further, the first p-side lightreflecting layer 31 p and the second p-side light reflecting layer 32 pmay be a single layer or stacked layers of these metal materials.

<Cover Electrode 40>

As shown in FIG. 9, the cover electrode 40 covers the first p-side lightreflecting layer 31 p and the second p-side light reflecting layer 32 p.In more detail, as shown in FIG. 6, the cover electrode 40 covers partof the upper surface of the first p-side light reflecting layer 31 p(the first p-side electrode) and the side surface thereof. Further, asshown in FIGS. 7 and 8, the cover electrode 40 covers part of the uppersurface of the second p-side light reflecting layer 32 p and the sidesurface thereof. The cover electrode 40 is a barrier layer forpreventing migration of metal materials that compose the first p-sidelight reflecting layer 31 p and the second p-side light reflecting layer32 p. The cover electrode 40 may be composed of metal oxide or metalnitride having a barrier property. For example, the cover electrode 40may be composed of at least one type of oxide or nitride selected fromthe group consisting of Si, Ti, Zr, Nb, Ta, and Al. Further, the coverelectrode 40 may be a single layer or stacked layers of these metalmaterials.

<Interlayer Insulating Film 50>

The interlayer insulating film 50 is an insulating film provided abovethe semiconductor stacked-layer body 20 for extending the first n-sideelectrode 61 n and the second n-side electrode 62 n electricallyconnected to the n-type semiconductor layer 21 n respectively above thep-type semiconductor layers 21 p and 22 p. Accordingly, as shown in FIG.10, the interlayer insulating film 50 is provided above substantiallythe entire surface of the semiconductor stacked-layer body 20. As shownin FIG. 6, above the first semiconductor region 21, the interlayerinsulating film 50 is provided at the upper and side surfaces of thecover electrode 40 and the side surface of the n-type semiconductorlayer 21 n. In the first semiconductor region 21, the interlayerinsulating film 50 has a p-side opening 51 p, and n-side openings 51 nat the bottom surfaces of the first holes 21 h on the n-typesemiconductor layer 21 n. As shown in FIG. 10, the n-side opening 51 nis circular, for example. Further, the p-side opening 51 p is providedin the region where the first p-side electrically conductive layer 61 pis disposed.

On the other hand, as shown in FIGS. 7 and 8, above the secondsemiconductor region 22, the interlayer insulating film 50 is providedat the upper and side surfaces of the cover electrode 40, and the sidesurface of the n-type semiconductor layer 21 n. In the secondsemiconductor region 22, the interlayer insulating film 50 has p-sideopenings 52 p, and n-side openings 52 n at the bottom surfaces of thesecond holes 22 h on the n-type semiconductor layer 21 n. Here, forexample, the n-side openings 52 n are circular. The p-side openings 52 pare quadrangular, for example. The p-side openings 52 p are provided atthe region where the second p-side electrically conductive layer 62 p isdisposed. Herein, a plurality of p-side openings 52 p are provided.

The interlayer insulating film 50 may be composed of metal oxide ormetal nitride. For example, the interlayer insulating film 50 may besuitably composed of at least one type of oxide or nitride selected fromthe group consisting of Si, Ti, Zr, Nb, Ta, and Al. Further, theinterlayer insulating film 50 may be a DBR (Distributed Bragg Reflector)film obtained by stacking two or more types of light-transmissivedielectrics differing from each other in the index of refraction.

<First N-side Electrode 61 n>

The first n-side electrode 61 n is an n-side pad electrode in the firstsemiconductor region 21 of the light emitting element 1. As shown inFIG. 6, the first n-side electrode 61 n is provided on part of theinterlayer insulating film 50, and extends to the first holes 21 h. Thefirst n-side electrode 61 n is connected to the n-type semiconductorlayer 21 n via the first holes 21 h. As shown in FIG. 11, the firstn-side electrode 61 n extends along a plurality of first holes 21 harranged at the first semiconductor region 21, and integrally connectsthe plurality of first holes 21 h.

The first n-side electrode 61 n is electrically connected to the n-typesemiconductor layer 21 n through the n-side openings 51 n of theinterlayer insulating film 50 in the first holes 21 h. Connecting thefirst n-side electrode 61 n to the n-type semiconductor layer 21 n atthe points in a wide area in the plane of the first semiconductor region21 allows the current supplied via the first n-side electrode 61 n to beevenly diffused into the n-type semiconductor layer 21 n at the firstsemiconductor region 21. Thus, the light emission efficiency improves.

<First P-side Electrically Conductive Layer 61 p>

The first p-side electrically conductive layer 61 p is a p-side padelectrode in the first semiconductor region 21 of the light emittingelement 1. As shown in FIG. 6, the first p-side electrically conductivelayer 61 p is provided on part of the interlayer insulating film 50, andextends to openings of the cover electrode 40.

The first p-side electrically conductive layer 61 p is provided on thefirst p-side light reflecting layer 31 p, and electrically connected tothe first p-side light reflecting layer 31 p through the openings of thecover electrode 40. Further, the first p-side electrically conductivelayer 61 p is electrically connected to the first p-type semiconductorlayer 21 p via the first p-side light reflecting layer 31 p. Thus, itcan be regarded that the first p-side electrically conductive layer 61 pforms the first p-side electrode with the first p-side light reflectinglayer 31 p.

The first p-side electrically conductive layer 61 p is electricallyconnected to the first p-side external connection electrode 81 p via aseed layer 85 through a p-side opening 71 p of the insulating protectivefilm 70.

<Second N-side Electrode 62 n>

The second n-side electrode 62 n is an n-side pad electrode in thesecond semiconductor region 22 of the light emitting element 1. As shownin FIG. 7, the second n-side electrode 62 n is provided on part of theinterlayer insulating film 50, and extends to the second holes 22 h. Thesecond n-side electrode 62 n is connected to the n-type semiconductorlayer 21 n via the second holes 22 h. As shown in FIG. 11, the secondn-side electrode 62 n extends along a plurality of second holes 22 harranged at the second semiconductor region 22, and integrally connectsthe plurality of second holes 22 h.

In each second hole 22 h, the second n-side electrode 62 n iselectrically connected to the n-type semiconductor layer 21 n throughthe n-side opening 52 n of the interlayer insulating film 50. Connectingthe second n-side electrode 62 n to the n-type semiconductor layer 21 nat the points in a wide area in the plane of the second semiconductorregion 22 allows the current supplied via the second n-side electrode 62n to be evenly diffused into the n-type semiconductor layer 21 n at thesecond semiconductor region 22. Thus, light emission efficiencyimproves.

<Second P-side Electrically Conductive Layer 62 p>

The second p-side electrically conductive layer 62 p is a p-side padelectrode in the second semiconductor region 22 of the light emittingelement 1. As shown in FIG. 8, the second p-side electrically conductivelayer 62 p is provided on part of the interlayer insulating film 50, andextends to the p-side openings 52 p of the interlayer insulating film50. Further, the second p-side electrically conductive layer 62 p iselectrically connected to the second p-side light reflecting layer 32 pthrough the p-side openings 52 p, and electrically connected to thesecond p-type semiconductor layer 22 p via the second p-side lightreflecting layer 32 p. Thus, it can be regarded that the second p-sideelectrically conductive layer 62 p forms the second p-side electrodewith the second p-side light reflecting layer 32 p. Further, the secondp-side electrically conductive layer 62 p is electrically connected tothe second p-side external connection electrode 82 p via the seed layer85 through a p-side opening 72 p of the insulating protective film 70.

The pad electrodes (the first n-side electrode 61 n, the second n-sideelectrode 62 n, the first p-side electrically conductive layer 61 p, andthe second p-side electrically conductive layer 62 p) may be composed ofa metal material. For example, the pad electrodes may be suitablycomposed of a single metal selected from Ag, Al, Ni, Rh, Au, Cu, Ti, Pt,Pd, Mo, Cr, and W, or alloy of which main component is such metal.Further preferably, the pad electrodes is composed of a single metalselected from Ag, Al, Pt, and Rh having excellent light reflectingproperty and alloy of which main component is such metal. Note that,when alloy is employed, the alloy may contain, as a constituent element,a non-metal element such as Si, as AlSiCu alloy does. Further, theelectrically conductive layers may each be a single layer or stackedlayers composed of these metal materials.

<Insulating Protective Film 70>

The insulating protective film 70 is an insulating film provided abovethe semiconductor stacked-layer body 20, for protecting the lightemitting element 1 from short-circuiting between the pad electrodes. Asshown in FIG. 12, the insulating protective film 70 has an n-sideopening 71 n at a position avoiding the first holes 21 h and the p-sideopening 71 p partially overlapping the p-side opening 51 p of theinterlayer insulating film 50, in the region where the externalconnection electrode 8 is disposed and above the first semiconductorregion 21.

As shown in FIG. 12, the insulating protective film 70 has an n-sideopening 72 n at a position including the second hole 22 h and a p-sideopening 72 p formed to include the p-side openings 52 p of theinterlayer insulating film 50, in the region where the externalconnection electrode 8 is disposed and above the second semiconductorregion 22.

Similarly to the interlayer insulating film 50, the insulatingprotective film 70 may be composed of metal oxide or metal nitride.

[External Connection Electrodes 8]

As shown in FIG. 5, the n-side external connection electrode 80 n isprovided on one side (left in FIG. 5) of the light emitting element 1which is quadrangular in a plan view. Further, the first p-side externalconnection electrode 81 p is provided on other side (upper right in FIG.5) opposing to the one side. Still further, the second p-side externalconnection electrode 82 p is also provided on the other side (lowerright in FIG. 5).

At the surface of the light emitting element 1, the first p-sideexternal connection electrode 81 p is spaced apart from the n-sideexternal connection electrode 80 n by a predetermined distance.Similarly, the second p-side external connection electrode 82 p isspaced apart from the n-side external connection electrode 80 n by apredetermined distance.

Herein, the shape of the n-side external connection electrode 80 n isapproximately rectangular in a plan view. The shape of the first p-sideexternal connection electrode 81 p and that of the second p-sideexternal connection electrode 82 p are each approximately square.Further, each p-side electrode is smaller than half the n-side electrodein the dimension.

Further, at the surface of the light emitting element 1, the firstp-side external connection electrode 81 p and the second p-side externalconnection electrode 82 p are symmetrically disposed relative to then-side external connection electrode 80 n.

Still further, at the surface of the light emitting element 1, the firstp-side external connection electrode 81 p and the second p-side externalconnection electrode 82 p are symmetrically disposed relative to eachother.

In this manner, the external connection electrodes 8 are freely disposedat desired positions independently of the disposition of the firstsemiconductor region 21 and the second semiconductor region 22 of thelight emitting element 1 and the disposition of the pad electrodes. Notethat, the n-side external connection electrode 80 n is connected to thefirst n-side electrode 61 n and the second n-side electrode 62 n.Further, the first p-side external connection electrode 81 p isconnected to the first p-side electrically conductive layer 61 p. Stillfurther, the second p-side external connection electrode 82 p isconnected to the second p-side electrically conductive layer 62 p.

The external connection electrodes 8 may be suitably composed of metalsuch as Cu, Au, or Ni. The external connection electrodes 8 may beformed by electroplating.

In mounting, a bonding member is provided between the externalconnection electrodes 8 and an external wiring pattern. Melting andthereafter cooling the bonding member strongly joins the externalconnection electrode 8 and the external wiring pattern to each other.Here, the bonding member may be solder such as Sn—Au, Sn—Cu, orSn—Ag—Cu. In this case, the uppermost layer of the external connectionelectrodes 8 is preferably composed of a material that can be tightlybonded to the employed bonding member.

[Operation of Light Emitting Device]

Next, with reference to FIGS. 1 to 8, a description will be given of theoperation of the light emitting device 100.

In the light emitting device 100, when an external power supply isconnected to the first p-side external connection electrode 81 p and then-side external connection electrode 80 n via the mounting substrate,current is supplied across the first p-side electrode (the first p-sidelight reflecting layer 31 p) and the first n-side electrode 61 n of thelight emitting element 1. This causes the first active layer 21 a of thelight emitting element 1 to emit light. The light propagates through thefirst semiconductor region 21 of the semiconductor stacked-layer body 20and is output from the upper surface or side surface of the lightemitting element 1 (see FIG. 3), thereby extracted to the outside. Notethat, the light propagating downward in the light emitting element 1 isreflected by the first p-side light reflecting layer 31 p and outputfrom the upper surface of the light emitting element 1, therebyextracted to the outside.

In the light emitting device 100, when the external power supply isconnected to the second p-side external connection electrode 82 p andthe n-side external connection electrode 80 n via the mountingsubstrate, current is supplied across the second p-side electrode (thesecond p-side light reflecting layer 32 p) and the second n-sideelectrode 62 n of the light emitting element 1. This causes the secondactive layer 22 a of the light emitting element 1 to emit light. Thelight propagates through the second semiconductor region 22 of thesemiconductor stacked-layer body 20 and is output from the upper surfaceor side surface of the light emitting element 1 (see FIG. 3), therebyextracted to the outside. Note that, the light propagating downward inthe light emitting element 1 is reflected by the second p-side lightreflecting layer 32 p and output from the upper surface of the lightemitting element 1, thereby extracted to the outside.

In the case where a blue-color light emitting diode is employed in thelight emitting device 100 and the first fluorescent material layer 91 ofthe wavelength conversion member 9 contains a YAG-based fluorescentmaterial, the light from the first semiconductor region 21 of the lightemitting element 1 is converted into white-color light through the firstfluorescent material layer 91. Further, when the second fluorescentmaterial layer 92 of the wavelength conversion member 9 contains anitride-based fluorescent material, the light from the secondsemiconductor region 22 of the light emitting element 1 is convertedinto reddish-color light through the second fluorescent material layer92.

Hence, in the light source 2, when just the first semiconductor region21 of the light emitting element 1 is caused to emit light, white-colorlight is output from the wavelength conversion member 9; when just thesecond semiconductor region 22 is caused to emit light, reddish-colorlight is output from the wavelength conversion member 9. Then, theFresnel lens 6 converges the light input thereto.

Further, in the light source 2, when the first semiconductor region 21and the second semiconductor region 22 of the light emitting element 1are simultaneously caused to emit light, both the white-color light andthe reddish-color light are output from the wavelength conversion member9, and the Fresnel lens 6 converges the received light of differentcolors. Thus, the light source 2 can emit light having been adjusted bydifferent fluorescent materials and exhibiting excellent color renderingwith improved naturalness.

Further, as shown in FIG. 1, in the light source 2, one Fresnel lens 6covers the entire light output surface of the concentrically formedfirst fluorescent material layer 91 and second fluorescent materiallayer 92 of the wavelength conversion member 9. This provides the lightsource 2 being reduced in size and having excellent appearance, forexample as compared to a conventional light source in which twocondenser lenses are juxtaposed to each other for respective fluorescentmaterial layers.

[Method of Manufacturing Light Emitting Device]

With reference to FIGS. 3 to 8 (and to FIGS. 9 to 12 as appropriate), adescription will be given of the overview of a method of manufacturingthe light emitting device 100. Firstly, the semiconductor stacked-layerbody 20 is formed by successively stacking, on the upper surface of thelight-transmissive substrate 10 composed of sapphire or the like, then-type semiconductor layer, the active layer, and the p-typesemiconductor layer which are composed of any of the semiconductormaterials described above (Step 101).

Further, on the entire semiconductor stacked-layer body 20, lightreflecting layers are formed by lift-off (Step 102). That is, a resistpattern having an opening corresponding to a region where the firstp-side light reflecting layer 31 p and the second p-side lightreflecting layer 32 p are disposed is formed by photolithography.Thereafter, the above-described metal film having an excellentreflecting property composed of Ag or the like is formed on the entirewafer by sputtering or vapor deposition. Removal of the resist patternpatterns the metal film. That is, the first p-side light reflectinglayer 31 p and the second p-side light reflecting layer 32 p having anopening are provided.

Next, the cover electrode 40 is formed to cover the upper and sidesurfaces of the first p-side light reflecting layer 31 p and those ofthe second p-side light reflecting layer 32 p (Step 103). The coverelectrode 40 is formed as follows. For example, an SiN film is formedover the entire wafer by sputtering or vapor deposition of SiN.Thereafter, a resist pattern having an opening except for a region wherethe cover electrode 40 is disposed is formed by photolithography.Etching the SiN film using the resist pattern as a mask patterns the SiNfilm. Thereafter, removal of the resist pattern provides the coverelectrode 40 having the opening.

Then, at part of the semiconductor stacked-layer body 20, the p-typesemiconductor layer, the active layer, and part of the n-typesemiconductor layer are removed by dry etching. Thus, the first hole 21h, the second hole 22 h, and the outer edge portion 22 s where then-type semiconductor layer 21 n is exposed are formed (Step 104: seeFIG. 9).

Next, the interlayer insulating film 50 is formed using a predeterminedinsulating material (Step 105: see FIG. 10).

Here, above the first semiconductor region 21, in forming the interlayerinsulating film 50 having the p-side opening 51 p, an opening is formedat the cover electrode 40 disposed in the region where the p-sideopening 51 p is formed. Accordingly, the p-side opening 51 p and theopening of the cover electrode 40 are opened by the substantiallyidentical dimension.

Further, above the second semiconductor region 22, in forming theinterlayer insulating film 50 having the p-side openings 52 p, openingsare formed at the cover electrode 40 disposed in the regions where thep-side openings 52 p are formed. Accordingly, the p-side openings 52 pand the openings of the cover electrode 40 are opened by thesubstantially identical dimension.

Note that, the interlayer insulating film 50 can be patterned asfollows. The insulating film is formed over the entire wafer bysputtering or the like. Thereafter, a resist pattern having the openingsat the predetermined regions is formed. Then, the insulating film ispatterned by etching.

Subsequently, as shown in FIG. 11, for example, on the interlayerinsulating film 50 by sputtering or the like, the first n-side electrode61 n and the first p-side electrically conductive layer 61 p are formedas the pad electrodes above the first semiconductor region 21, and thesecond n-side electrode 62 n and the second p-side electricallyconductive layer 62 p are formed as the pad electrodes above the secondsemiconductor region 22 (Step 106). These pad electrodes can bepatterned by, for example, lift-off. Thus, the light emitting element 1is manufactured as a wafer. Herein, subsequently, the insulatingprotective film 70 is formed using a predetermined insulating materialon the pad electrodes (Step 107: see FIG. 12). The insulating protectivefilm 70 can be formed similarly to the interlayer insulating film 50.Note that, while the insulating protective film 70 is not essential forthe light emitting element 1, it is preferably provided.

Next, the pad electrodes are covered by a mask having openings at theregions where the external connection electrodes 8 are disposed (Step108). This mask is an insulating mask for preventing plating on theregions where the external connection electrodes 8 are not disposed in alater step. The mask is composed of an insulating material such asphotoresist or SiO₂.

Next, the seed layers 85 (see FIG. 5) each serving as the current pathin electroplating are formed inside the openings of the mask (Step 108),and the external connection electrodes 8 are formed by electroplating onthe seed layers 85 (Step 109).

Then, the mask is removed using any appropriate solvent or agent (Step110). Note that, the mask can be removed also by dry etching.

Finally, the wafer is cut along boundaries by dicing or scribing into aplurality of singulated light emitting devices 100 (Step 111).

Next, a description will be given of the overview of a method ofmanufacturing a light emitting device having the wavelength conversionmember 9 such as shown in FIGS. 2 and 3.

Firstly, a plate-like reflective member is provided (Step 201). Thereflective member is made of cured resin containing a light reflectingsubstance, and having a size corresponding to the plurality ofsingulated light emitting devices.

Then, openings (for example, through holes) each having a shapeconforming to the outer circumferential edge of the wavelengthconversion member 9 are formed at the provided reflective member (Step202). This provides a reflective member frame in which the lightreflecting members 7 a of the wavelength conversion members 9 arecoupled. Here, the openings may be formed by, for example, laser lightirradiation, punching, etching, or blasting.

Next, each of the opening in the reflective member frame is filled withlight-transmissive resin composing the light-transmissive member 93 ofthe wavelength conversion member 9 by potting, for example. Thelight-transmissive resin is cured, and a plurality of light-transmissivemembers are formed (Step 203).

Subsequently, in each of the cured light-transmissive members in thereflective member frame, a first opening having a shape corresponding tothe first fluorescent material layer 91 of the wavelength conversionmember 9 is formed, and a second opening having a shape corresponding tothe second fluorescent material layer 92 is formed (Step 204).

Then, in the reflective member frame, each first opening is filled withresin containing the first fluorescent material by potting, for example,and each second opening is filled with resin containing the secondfluorescent material (Step 205).

Thereafter, for example by centrifuging, the first fluorescent materialand the second fluorescent material are settled (Step 206).

Further, the resins are cured in the state where the first fluorescentmaterial and the second fluorescent material are settled. Thus, acomposite sheet made up of the reflective member frame and thewavelength conversion members 9 is formed (Step 207).

Subsequently, the light emitting devices 100 are bonded to the compositesheet (Step 208). Specifically, the light-transmissive substrate 10 ofeach light emitting element 1 is bonded to the composite sheet with, forexample, die-bonding resin being light-transmissive resin. At this time,it is preferable that the light emitting element 1 is bonded to thelower surface of the wavelength conversion member 9 so that light can beeffectively extracted via the wavelength conversion member 9.

Then, resin including a light reflecting substance is caused to coverthe light emitting devices 100 bonded to the composite sheet includingthe external connection electrodes 8, and be cured. Thus, a reflectivemember is formed on the composite sheet (Step 209).

Next, the upper surface of the reflective member covering the lightemitting devices 100 is polished, to expose the external connectionelectrodes 8 of each light emitting element 1 (Step 210).

Then, the composite sheet and the reflective member thereon are cut intoindividual light emitting devices by dicing or the like along thedivision lines of the reflective member frame (Step 211).

The foregoing steps provide the light emitting device in which the lightreflecting member 7 a is formed around the wavelength conversion member9 and the light reflecting member 7 b is formed around the lightemitting device 100.

In the light emitting device 100, the external connection electrodes 8include the n-side external connection electrode 80 n connected to thefirst n-side electrode 61 n and the second n-side electrode 62 n, thefirst p-side external connection electrode 81 p connected to the firstp-side electrode (the first p-side light reflecting layer 31 p), and thesecond p-side external connection electrode 82 p connected to the secondp-side electrode (the second p-side light reflecting layer 32 p).

Further, in the light emitting device 100, the first semiconductorregion 21 serving as the first light emitting portion is formed at thecentral region of the light emitting element 1 in a plan view. The firstsemiconductor region 21 is provided with the first n-side electrode 61 nbeing the n-side pad electrode, and the first p-side electricallyconductive layer 61 being the p-side pad electrode.

Still further, in the light emitting device 100, the secondsemiconductor region 22 serving as the second light emitting portion isformed around the first semiconductor region 21 in a plan view. Thesecond semiconductor region 22 is provided with the second n-sideelectrode 62 n being the n-side pad electrode, and the second p-sideelectrically conductive layer 62 being the p-side pad electrode.Accordingly, the light emitting device 100 is provided with the n-sideand p-side pad electrodes for each of the light emitting portions.

Thus, the light emitting device 100 can supply current to each of thefirst semiconductor region 21 (the first light emitting portion) wherethe first p-type semiconductor layer 21 p is stacked above one n-typesemiconductor layer 21 n, and the second semiconductor region 22 (thesecond light emitting portion) provided around the first semiconductorregion 21 and where the second p-type semiconductor layer 22 p isstacked above the one n-type semiconductor layer 21 n, via the externalconnection electrodes 8. Accordingly, the first light emitting portionand the second light emitting portion can be controlled independently ofeach other.

On the other hand, in the conventional technique as disclosed inWO2009/019836 where a sole n-side electrode (a cathode electrode) isconnected to the first light emitting portion (an edge portion) or thesecond light emitting portion (a region inner than the edge portion),what is obtained is the current density distribution in which thecurrent flows densely in the light emitting portion where the n-sideelectrode is connected, and the current density tends to become higherat a point nearer to the n-side electrode also in the plane of each ofthe light emitting portions.

In contrast, with the light emitting device 100 according to the presentembodiment, different n-side electrodes (the first n-side electrode 61 nand the second n-side electrode 62 n) are respectively connected to thefirst semiconductor region 21 (the first light emitting portion) and thesecond semiconductor region 22 (the second light emitting portion).

Accordingly, with the light emitting element 1 according to the presentembodiment, the current path from the first n-side electrode 61 n to thefirst p-side electrode (the first p-side light reflecting layer 31 p) inthe first semiconductor region 21 and the current path from the secondn-side electrode 62 n to the second p-side electrode (the second p-sidelight reflecting layer 32 p) in the second semiconductor region 22 canbe well balanced with each other. Hence, the light emitting element 1can reduce unevenness in current than the conventional light emittingelement. The light emitting element 1 having the current density withreduced unevenness improves the light emission intensity distribution ofthe light emitting device 100 using the light emitting element 1.

Second Embodiment

As shown in FIGS. 13 and 14, a light emitting element 1B and a lightemitting device 100B according to the second embodiment are differentfrom the light emitting element 1 and the light emitting device 100according to the first embodiment in the openings of the interlayerinsulating film 50. In the following, constituent members similar tothose of the light emitting device 100 are denoted by like referencecharacters, and the description thereof will not be repeated.

The light emitting device 100B includes the light emitting element 1B,the external connection electrodes 8 (the n-side external connectionelectrode 80 n, the first p-side external connection electrode 81 p, andthe second p-side external connection electrode 82 p).

In the light emitting element 1B, the interlayer insulating film 50includes n-side openings 53 n on the outer circumference side of thesecond semiconductor region 22 (left in FIG. 14). Herein, the outer edgeportion 22 s of the n-type semiconductor layer 21 n is positioned outerthan the second p-type semiconductor layer 22 p in a plan view. As shownin FIG. 14, the second n-side electrode 62 n extends from above theouter edge portion of the second p-type semiconductor layer 22 p ontothe outer edge portion 22 s of the n-type semiconductor layer 21 n. Thesecond n-side electrode 62 n is connected to the outer edge portion 22 sof the n-type semiconductor layer 21 n, and capable of reflecting light,which will otherwise be extracted from the side surface of the secondp-type semiconductor layer 22 p, toward the light extraction surface. Asshown in FIG. 13, part of the second n-side electrode 62 n is disposedalong the second p-type semiconductor layer 22 p in a plan view.

In the light emitting element 1B according to the second embodiment, thesecond n-side electrode 62 n is in contact with the n-type semiconductorlayer 21 n in the second holes 22 h, and also in contact with the outeredge portion 22 s of the semiconductor stacked-layer body 20 through then-side openings 53 n of the interlayer insulating film 50.

In the light emitting element 1B, the second n-side electrode 62 n is incontact with the n-type semiconductor layer 21 n at the outer edgeportion 22 s of the semiconductor stacked-layer body 20 in this manner.Therefore, the light emitting device 100B using the light emittingelement 1B suppresses an increase in the forward voltage, and improvesthe light emission output.

Third Embodiment

As shown in FIGS. 15 and 16, a light emitting element 1C and a lightemitting device 100C according to a third embodiment are different fromthe light emitting element 1 and the light emitting device 100 accordingto the first embodiment in including two semiconductor stacked-layerbodies. In the following, constituent members similar to those of thelight emitting device 100 are denoted by like reference characters, andthe description thereof will not be repeated.

The light emitting device 100C includes the light emitting element 1C,and the external connection electrodes 8 (the n-side external connectionelectrode 80 n, the first p-side external connection electrode 81 p, andthe second p-side external connection electrode 82 p).

In the first embodiment, the n-type semiconductor layer is continuouslyformed across the first semiconductor region 21 and the secondsemiconductor region 22. On the other hand, in the third embodiment, then-type semiconductor layer is separated between the first semiconductorregion 21 and the second semiconductor region 22. Accordingly, the firstsemiconductor region 21 is also referred to as the first semiconductorstacked-layer body 21. Further, the second semiconductor region 22 isalso referred to as the second semiconductor stacked-layer body 22C.

As shown on the right side in FIG. 16, the first semiconductorstacked-layer body 21 includes the first n-type semiconductor layer 21n, the first active layer 21 a, and the first p-type semiconductor layer21 p, which are provided on the light-transmissive substrate 10.

As shown on the left side in FIG. 16, the second semiconductorstacked-layer body 22C includes a second n-type semiconductor layer 22n, the second active layer 22 a, and the second p-type semiconductorlayer 22 p, which are provided on the light-transmissive substrate 10.

As shown in FIG. 16, in the light emitting element 1C, between the firstsemiconductor stacked-layer body 21 (the first light emitting portion)and the second semiconductor stacked-layer body 22C (the second lightemitting portion), the p-type semiconductor layer, the active layer, andthe n-type semiconductor layer are removed above the light-transmissivesubstrate 10. On the light-transmissive substrate 10 where thesesemiconductor layers are removed, the interlayer insulating film 50 andthe like are stacked.

Thus, the light emitting device 100C can supply current to each of thefirst semiconductor stacked-layer body 21 (the first light emittingportion) above the first n-type semiconductor layer 21 n where the firstp-type semiconductor layer 21 p is stacked, and the second semiconductorstacked-layer body 22C (the second light emitting portion) providedaround the first light emitting portion and located above the secondn-type semiconductor layer 22 n where the second p-type semiconductorlayer 22 p is stacked, via the external connection electrodes 8.Accordingly, the first light emitting portion and the second lightemitting portion can be controlled independently of each other.

Further, in the light emitting device 100C, since the firstsemiconductor stacked-layer body 21 and the second semiconductorstacked-layer body 22C are separated from each other on thelight-transmissive substrate 10, the light laterally propagating in then-type semiconductor layers 21 n and 22 n can be reflected at theseparation end surfaces 21 e and 22 e (see FIG. 16). Thus, in the casewhere the first fluorescent material layer 91 and the second fluorescentmaterial layer 92 are provided on the light extraction surface side (onthe lower side in FIG. 16) of the light emitting element 1C, it becomespossible to more selectively cause the first fluorescent material layer91 and the second fluorescent material layer 92 to emit light.

Fourth Embodiment

As shown in FIG. 17, a light emitting device 100D according to a fourthembodiment is different from the light emitting device 100 according tothe first embodiment in the structure of the external connectionelectrodes 8. In the following, the constituent members similar to thoseof the light emitting device 100 are denoted by like referencecharacters, and the description thereof will not be repeated.

The light emitting device 100D includes a light emitting element 1D, andas the external connection electrodes 8 provided at the light emittingelement 1D, includes a first n-side external connection electrode 81 n,a second n-side external connection electrode 82 n, and a p-sideexternal connection electrode 80 p.

While the light emitting element 1D includes constituent members similarto those of the light emitting element 1, they may be different fromeach other, for example, in the position of the through holes of thep-type semiconductor layers and that of the through holes of theinsulating film. For example, in the insulating protective film 70, theshape, size, and disposition of the p-side opening 71 p and the n-sideopening 71 n are different from the light emitting element 1 accordingto the first embodiment. In particular, the n-side opening 71 n of theinsulating protective film 70 is provided at the area where the firstn-side external connection electrode 81 n is disposed, and at theposition avoiding the first holes 21 h above the first semiconductorregion 21. Note that, the shape, size, and disposition of the n-sideopening 71 n are not limited to those shown in FIG. 17. The lightemitting element 1D structured as described above can also reduceunevenness in the current than the conventional light emitting element.

Disposition of the external connection electrodes 8 of the lightemitting device 100D is identical to that of the external connectionelectrodes 8 of the light emitting device 100 being rotated by 180degrees in a plan view. That is, as shown in FIG. 17, the first n-sideexternal connection electrode 81 n is provided on one side (lower leftin FIG. 17) of the quadrangular light emitting element 1 in a plan view.Further, the second n-side external connection electrode 82 n also isprovided on the one side (upper left in FIG. 17). On the other hand, thep-side external connection electrode 80 p is provided on other sideopposing to the one side (right in FIG. 17).

The first n-side external connection electrode 81 n is connected to thefirst n-side electrode 61 n through the n-side opening 71 n of theinsulating protective film 70.

The second n-side external connection electrode 82 n is connected to thesecond n-side electrode 62 n through the n-side opening 72 n of theinsulating protective film 70.

The light emitting device 100D structured as described above can alsoimprove the light emission intensity distribution through use of thelight emitting element 1D.

Fifth Embodiment

As shown in FIG. 18, a light emitting device 100E according to a fifthembodiment is different from the light emitting device 100D according tothe fourth embodiment in the structure of the external connectionelectrodes 8. In the following, the constituent members similar to thoseof the light emitting device 100D are denoted by like referencecharacters, and the description thereof will not be repeated.

The light emitting device 100E includes a light emitting element 1E, andas the external connection electrodes 8 provided at the light emittingelement 1E, includes the first n-side external connection electrode 81n, the second n-side external connection electrode 82 n, the firstp-side external connection electrode 81 p, and the second p-sideexternal connection electrode 82 p.

Note that, the light emitting element 1E is identical to the lightemitting element 1D shown in FIG. 17.

The first p-side external connection electrode 81 p is connected to thefirst p-side electrically conductive layer 61 p through the p-sideopening 71 p of the insulating protective film 70. That is, the firstp-side external connection electrode 81 p is connected to the firstp-side electrode (the first p-side light reflecting layer 31 p) via thefirst p-side electrically conductive layer 61 p.

The second p-side external connection electrode 82 p is connected to thesecond p-side electrically conductive layer 62 p through the p-sideopening 72 p of the insulating protective film 70. That is, the secondp-side external connection electrode 82 p is connected to the secondp-side electrode (the second p-side light reflecting layer 32 p) via thesecond p-side electrically conductive layer 62 p.

Such a four-terminal type light emitting device 100E can also improvethe light emission intensity distribution through use of the lightemitting element 1E.

In the foregoing, several embodiments of the present invention have beenexemplary shown. However, it goes without saying that the presentinvention is not limited to the above-described embodiments, and can bein any mode without departing from the spirit of the present invention.

For example, the light emitting device may include the wavelengthconversion member 9, and may further include the Fresnel lens 6.

The shape of the upper surface of the wavelength conversion member 9 isnot limited to quadrangular, and it may be circular, elliptic, orrounded quadrangular. The shape of the upper surface of the wavelengthconversion member 9 can be changed as appropriate, taking intoconsideration of the combination of a secondary optical system with theemployed lens or the like. The light output surface of the wavelengthconversion member 9 is not limited to be flat, and it may be a concavesurface or a convex surface. The light output surface of the wavelengthconversion member 9 may be uneven.

For example, the light emitting device 100 may have a structure inwhich, at the outer edge portion 22 s of the semiconductor stacked-layerbody 20 in a plan view, the p-type semiconductor layer, the active layerand the n-type semiconductor layer are removed above thelight-transmissive substrate 10. In this case, the light emitting devicehas the structure in which, at the outer circumference of the secondsemiconductor region 22, the interlayer insulating film 50 and othersare stacked on the light-transmissive substrate 10 without having thesemiconductor layers interposed. Therefore, the thickness of the outercircumferential portion of the light emitting device reduces. In thecase where a light emitting device including the wavelength conversionmember 9 is manufactured using this light emitting device, in Step 209where the light emitting device bonded to the composite sheet is coveredby the resin containing the light reflecting substance, the reducedthickness of the outer circumferential portion of the light emittingdevice (the region indicated by reference character 302 in FIG. 3)advantageously facilitates distribution of the resin containing thelight reflecting substance (the material of the light reflecting member7 b). The light emitting devices 100B, 100D, and 100E can be similarlymodified.

Similarly, the light emitting device 100C may have a structure in which,at the outer edge portion 22 s of the second semiconductor stacked-layerbody 22C, the p-type semiconductor layer, the active layer, and then-type semiconductor layer are removed above the light-transmissivesubstrate 10.

The light emitting devices 100C, 100D, and 100E can be modified toinclude the n-side openings 53n of the interlayer insulating film 50shown in FIG. 13.

For example, the external connection electrodes 8 of the light emittingdevice 100 may have a stacked-layer structure composed of a plurality oftypes of metals. In particular, the upper surface of each of theexternal connection electrodes 8 serves as the mounting surface.Accordingly, at least the uppermost layer is preferably composed of Au,in order to prevent corrosion and to improve bondability with themounting substrate using an Au-alloy-based bonding member such as Au—Sneutectic solder. Further, in the case where the lower layer portion ofeach of the external connection electrodes 8 is composed of metal otherthan Au, such as Cu, the upper layer portion may have a stacked-layerstructure such as Ni/Au or Ni/Pd/Au, in order to improve adhesion withAu. Further, the upper surface of each of the external connectionelectrodes 8 may be uneven.

What is claimed is:
 1. A light emitting element comprising: alight-transmissive substrate; a first semiconductor stacked-layer bodyhaving a first n-type semiconductor layer provided above part of thelight-transmissive substrate, and a first p-type semiconductor layerprovided above the first n-type semiconductor layer, the first p-typesemiconductor layer being provided with a first hole in which the firstn-type semiconductor layer is exposed from the first p-typesemiconductor layer; a first p-side electrode provided on the firstp-type semiconductor layer; a first n-side electrode having a portionabove the first p-side electrode, extending into the first hole, andbeing directly connected to the first n-type semiconductor layer via thefirst hole; a second semiconductor stacked-layer body having a secondn-type semiconductor layer provided above the light-transmissivesubstrate and surrounding the first semiconductor stacked-layer body ina plan view, and a second p-type semiconductor layer provided above thesecond n-type semiconductor layer, the second p-type semiconductor layerbeing provided with a second hole in which the second n-typesemiconductor layer is exposed from the second p-type semiconductorlayer; a second p-side electrode provided on the second p-typesemiconductor layer; and a second n-side electrode having a portionabove the second p-side electrode, extending into the second hole, andbeing directly connected to the second n-type semiconductor layer viathe second hole.
 2. The light emitting element according to claim 1,wherein an outer edge portion of the second n-type semiconductor layeris positioned outer than the second p-type semiconductor layer in a planview, and the second n-side electrode extends from above an outer edgeportion of the second p-type semiconductor layer onto the outer edgeportion of the second n-type semiconductor layer.
 3. The light emittingelement according to claim 2, wherein part of the second n-sideelectrode extending on the outer edge portion of the second n-typesemiconductor layer is connected to the outer edge portion of the secondn-type semiconductor layer along the second p-type semiconductor layerin a plan view.
 4. The light emitting element according to claim 2,wherein the second n-side electrode includes at least one type selectedfrom Ag, Al, Pt, and Rh.
 5. The light emitting element according toclaim 1, wherein a plurality of the first holes are arranged along anouter edge portion of the first p-type semiconductor layer.
 6. The lightemitting element according to claim 5, wherein the first n-sideelectrode extends along the arranged first holes and integrally connectsthe first holes.
 7. The light emitting element according to claim 1,wherein a plurality of the second holes are arranged along an inner edgeportion of the second p-type semiconductor layer.
 8. The light emittingelement according to claim 7, wherein the second n-side electrodeextends along the arranged second holes and integrally connects thesecond holes.
 9. A light emitting device comprising: the light emittingelement according to claim 1; and an external connection electrodeprovided at the light emitting element on a side opposite to thelight-transmissive substrate, wherein the external connection electrodeincludes: an n-side external connection electrode connected to the firstn-side electrode and the second n-side electrode; a first p-sideexternal connection electrode connected to the first p-side electrode;and a second p-side external connection electrode connected to thesecond p-side electrode.
 10. The light emitting device according toclaim 9, wherein the first p-side electrode of the light emittingelement includes: a first p-side light reflecting layer connected tosubstantially an entire upper surface of the first p-type semiconductorlayer; and a first p-side electrically conductive layer provided on thefirst p-side light reflecting layer and connected to the first p-sideexternal connection electrode.
 11. The light emitting device accordingto claim 10, wherein the first p-side light reflecting layer contains atleast one type selected from Ag, Al, Pt, Rh, and Ir.
 12. The lightemitting device according to claim 9, wherein the second p-sideelectrode of the light emitting element includes: a second p-side lightreflecting layer connected to substantially an entire upper surface ofthe second p-type semiconductor layer; and a second p-side electricallyconductive layer provided on the second p-side light reflecting layerand connected to the second p-side external connection electrode. 13.The light emitting device according to claim 12, wherein the secondp-side light reflecting layer contains at least one type selected fromAg, Al, Pt, Rh, and Ir.
 14. The light emitting device according to claim9, wherein the first p-type semiconductor layer of the light emittingelement has a circular outer edge in a plan view.
 15. The light emittingdevice according to claim 9, wherein the second p-type semiconductorlayer of the light emitting element has a circular outer edge in a planview.
 16. The light emitting device according to claim 9, furthercomprising a wavelength conversion member opposing to thelight-transmissive substrate of the light emitting element, wherein thewavelength conversion member includes, in a plan view, a firstfluorescent material layer covering the first p-type semiconductorlayer; and a second fluorescent material layer provided around the firstfluorescent material layer and covers the second p-type semiconductorlayer.
 17. The light emitting device according to claim 16, wherein awavelength of light of the light emitting element having converted bythe second fluorescent material layer is longer than a wavelength oflight of the light emitting element having converted by the firstfluorescent material layer.
 18. The light emitting device according toclaim 16, further comprising a Fresnel lens provided on a side oppositeto the light-transmissive substrate with reference to the wavelengthconversion member.
 19. A light emitting device comprising: the lightemitting element according to claim 1; and an external connectionelectrode provided at the light emitting element on a side opposite tothe light-transmissive substrate, wherein the external connectionelectrode includes: a first n-side external connection electrodeconnected to the first n-side electrode; a second n-side externalconnection electrode connected to the second n-side electrode; and ap-side external connection electrode connected to the first p-sideelectrode and the second p-side electrode.
 20. A light emitting devicecomprising: the light emitting element according to claim 1; and anexternal connection electrode provided at the light emitting element ona side opposite to the light-transmissive substrate, wherein theexternal connection electrode includes: a first n-side externalconnection electrode connected to the first n-side electrode; a secondn-side external connection electrode connected to the second n-sideelectrode; a first p-side external connection electrode connected to thefirst p-side electrode; and a second p-side external connectionelectrode connected to the second p-side electrode.
 21. A light emittingelement comprising: a light-transmissive substrate; an n-typesemiconductor layer provided above the light-transmissive substrate; afirst p-type semiconductor layer provided above part of the n-typesemiconductor layer and having a first hole in which the n-typesemiconductor layer is exposed from the first p-type semiconductorlayer; a first p-side electrode provided on the first p-typesemiconductor layer; a first n-side electrode having a portion above thefirst p-side electrode, extending into the first hole, and beingdirectly connected to the n-type semiconductor layer via the first hole;a second p-type semiconductor layer provided above the n-typesemiconductor layer and surrounding the first p-type semiconductor layerin a plan view, the second p-type semiconductor layer having a secondhole in which the n-type semiconductor layer is exposed from the secondp-type semiconductor layer; a second p-side electrode provided on thesecond p-type semiconductor layer; and a second n-side electrode havinga portion above the second p-side electrode, extending into the secondhole, and being directly connected to the n-type semiconductor layer viathe second hole.
 22. The light emitting element according to claim 21,wherein an outer edge portion of the n-type semiconductor layer ispositioned outer than the second p-type semiconductor layer in a planview, and the second n-side electrode extends from above an outer edgeportion of the second p-type semiconductor layer onto the outer edgeportion of the n-type semiconductor layer.
 23. The light emittingelement according to claim 22, wherein part of the second n-sideelectrode extending on the outer edge portion of the n-typesemiconductor layer is connected to the outer edge portion of the n-typesemiconductor layer along the second p-type semiconductor layer in aplan view.